Field of the Invention
[0001] The present invention relates to a powder, more particularly, to a composite powder
comprising rubber particles and inorganic particles, preparation and use thereof,
Background of the invention
[0002] The International Patent Publication WO 01/40356A1(filed on September 18, 2000, claiming
the benefit of the Chinese Patent Application No. 99125530:5 filed by the present
applicants on December 3, 1999) discloses a fully vulcanized powdery rubber, which
means discrete, fine rubber powders having a gel content of 60 percent by weight or
more and freely flowing after drying without any partitioning agents. Such powdery
rubbers, are obtained by irradiating a rubber latex in the absence or presence of
a cross-linking agent so as to cross-link them and fix the particle size of the rubber
particles, and then subjecting the irradiated latex to precipitation or spray drying.
The fully vulcanized powdery rubber thus obtained has a particle size in the range
of from 20 to 2000nm and can be used as tougheners for plastics, with excellent toughening
effects being achieved. However, when such a powdery rubber is used for toughening
plastics, the strength, modulus and thermal properties inherent in the plastics are
frequently reduced.
[0003] Since 1980s, inorganic particles have been proposed for modifying plastics. However,
Inorganic particles have a very high sulface energy, thus if no special treatment
is conducted, they are apt to agglomerate when blending with plastics, which will
significantly decrease their modification effects on plastics. For example, nano-clay
materials are now being used for enhancing the rigidity of polyamides, with polyamide/clay
nano-composites being obtained(see, for example, "Polymers-Inorganics Nano-composites",
Series of Nano-materials and Application Technologies, the Chemical and Industrial
Press, Dec., 2002). The clays used for preparing polyamide/clay nano-composites are
conventionally sheet clays, which possess a layered structure in a nanometric scale,
are natural nano-materials and are very suitable for preparing nano-composites. However,
the gaps among the layers of the sheet clays are very small, thus it is Impossible
for organic polymers to enter said gaps to exfoliate the sheet clays in a nanometric
scale. Therefore, before used for preparing such polymer/clay nano-composites, clays
must be subjected to a special treatment, i.e., displacement by various organic substances,
thereby obtaining nano-precursor materials containing organic functional groups, which
are then compounded with polymers to form nano-composites. The process for preparing
such nano-precursor materials is also called organo-modification of clays. After such
an organo-modification, organic functional groups, such as organic cations and the
like, are introduced to the gaps of the sheet clays, which facilitates the insertion
of monomers or polymers(see, for example, "Polymer-Inorganics Nano-composites", pp.
21-22). By intercalation-compounding, the layers of sheet clays subjected to organo-
modification can be dispersed in polymer matrix in a nanometric scale, thereby obtaining
polymer/clay nano-composites, which possess high strength, modulus, heat distortion
temperature. The organo-modification of montmorillonite facilitates the intercalation-compounding
and however, renders the preparation of composites complicated.
Disclosure of the invention
[0004] In view of the above, the present inventors conducted extensive and intensive researches
in the field of toughening plastics, with a view of developing a novel toughener which
can be used to toughen plastics and meanwhile, retains the strength, modulus and thermal
properties inherent in plastics. As a result of many experiments, the present inventors
found that by compounding powdery rubbers with inorganic particles, a composite powder
comprising organic elastic particles and inorganic rigid particles can be obtained,
and:when blending with plastics, the organic elastic particles contained in such a
composite powder prevent the agglomeration of inorganic particles, thus a better toughening
effect can be achieved by toughening plastics with such a composite powder, compared
to using elastic particles or inorganic particles alone, and meanwhile, the negative
effects on rigidity and heat resistance of resins caused by the introduction of elastic
particles are reduced. Furthermore, such a composite powder can be advantageously
used for the preparation of thermoplastic elastomers.
[0005] Therefore, an object of the present invention is to provide a composite powder, which
can be used for toughening plastics and for preparing thermoplastic elastomers.
[0006] Another object of the present Invention is to provide a process for preparing the
composite powder according to the present invention.
[0007] Still another object of the present invention is to provide use of the composite
powder according to the present invention for preparing toughened plastics and thermoplastic
elastomers.
[0008] The present invention in its one aspect provides a composite powder, comprising powdery
rubber particles having a cross-linked structure and inorganic particles distributed
between said rubber particles.
[0009] The present invention in its second aspect provides a process for preparing the composite
powder according to the present invention, comprising intimately mixing an irradiated
or non-irradiated rubber latex with a slurry of inorganic particles in a ratio corresponding
to that of rubber particles to inorganic particles In the composite powder according
to the present invention, and then drying the resultant mixture.
[0010] The present invention in its third aspect provides plastics toughened by the composite
powder according to the present invention.
[0011] The present Invention in its fourth aspect provides thermoplastic elastomers comprising
the composite powder according to the present invention.
[0012] These and other objects, features and advantages of the present invention will be
apparent after reading the whole description in conjunction with the drawings.
Brief description of drawings
[0013]
Figure 1 is a transmission electron micrograph of the sample obtained in Example 15,
in which the shadow stands for agglomerates composed of rubber particles and inorganic
particles, which are dispersed, in the plastic matrix, with the darker spots in the
shadow being inorganic particles dispersed in agglomerated rubber particles.
Figure 2 is a transmission electron micrograph of the sample obtained In Example 17,
in which the shadow stands for agglomerates composed of rubber particles and inorganic
particles, which are dispersed in the plastic matrix, with the darker spots in the
shadow being inorganic particles dispersed in agglomerated rubber particles.
Figure 3 is a transmission electron micrograph of the sample obtained in Example 14,
in which the circular shadow stands for butadiene-styrene-vinylpyridine rubber particles
and the strip-shaped shadow stands for sodium-based montmorillonite, with the rubber
particles and montmorillonite being uniformly dispersed in the polyamide matrix and
at the same time, the sheet montmorillonite being completely exfoliated in the matrix.
Detailed description of the invention
[0014] The composite powder according to the present invention comprises powdery rubber
particles having a cross-linked structure and inorganic particles distributed between
said rubber particles, wherein the weight ratio of said rubber particles to said inorganic
particles is from 99.5 : 0.5 to 20 : 80, preferably from 99 : 1 to 50 : 50.
[0015] In the composite powder according to the present invention, the inorganic particles
are those commercially available in the prior art. There are no restrictions on the
type of the inorganic particles as long as the size thereof falls within the scope
of the present invention. However, the inorganic particles which are unstable when
encountering water are excluded. The inorganic particles can be of any shape, such
as spheres, ellipsoids; sheets, needles or irregular shapes. In the view of three-dimensional
point, the individual particles have an average size of from 0.2 to 500nm, preferably
from 0.5 to 100nm in at least one dimension.
[0016] The inorganic particles used in the composite powder according to the present invention
can be selected from elemental metals or alloys thereof, such as gold, silver, cupper,
iron or alloys thereof; metal oxides, such as aluminum oxide(Al
2O
3), magnesium oxide(MgO), titanium dioxide(TiO
2), iron sesquioxide(Fe
2O
3), ferroferric oxide(Fe
3O
4), silver oxide(Ag
2O), zinc oxide(ZnO) and the like; metal or non-metal nitrides, such as aluminum nitride(AIN),
silicon nitride(SiN
4) and the like; non-metal carbides, such as silicon carbide(SIC) and the like; non-metal
oxides, such as silicon dioxide(SiO
2) and the like; metal hydroxides, such as aluminum hydroxide(Al(OH)
3), magnesium hydroxide(Mg(OH)
2) and the like; metal salts, including metal carbonates, silicates, sulfates and the
like, such as calcium carbonate(CaCO
3), barium sulfate(BaSO
4), calcium sulfate(CaSO
4), silver chloride(AgCl) and the like; mineral earths, such as asbestos, talc, kaolin,
mica, feldspar, wollastonite, montmorillonite and the like; and the mixtures of two
or more of them.
[0017] The powdery rubber particles having a cross-linked structure used in the composite
powder according to the present invention are those having a homogeneous structure,
that is to say, Individual particles are homogeneous in their composition and no heterogeneous
phenomena, such as demixing, phase separation or the like can be observed in the particles
by current microscopic technologies. In addition, the powdery rubber particles have
a gel content of 60 percent by weight or more, preferably 75 percent by weight or
more, more preferably 80 percent by weight or more.
[0018] The composite powder according, to the present invention can be prepared by the process
for preparing fully vulcanized powdery rubbers disclosed in the International Patent
Publication WO 01/40356A1 filed by the present applicants on September 18, 2000(its
full text is incorporated herein by reference), except that the irradiated latex is
admixed with a slurry of inorganic particles prior to drying.
[0019] In addition,the composite powder according to the present invention can also be prepared
by the process for preparing powdery cross-linked rubbers disclosed in Chinese Patent
Application No. 00130386.4 filed by the present applicants on November 3, 2000(CN
1353131A, its full text is incorporated herein by reference), except that cross-linked
rubber latexes are admixed with a slurry of inorganic particles prior to drying.
[0020] The composite powder according to the present invention can optionally comprise water-soluble
nucleating agents for plastics and if such agents are present, the amount thereof
is such that the weight ratio of the rubber particles to the nucleating agent in the
composite powder according to the present invention is from 99 : 1 to 5.0 : 50, preferably
from 97 : 3 to 70 : 30. The nucleating agent can be those conventionally employed
in the art, preferably sodium benzoate.
[0021] The composite powder according to the present invention comprises agglomerates composed
of powdery rubber particles and inorganic particles; with Inorganic particles being
uniformly distributed either inside the agglomerats or both inside the agglomerates
and on the surfaces thereof, wherein the rubber particles themselves have a gel content
of 60 percent by weight or more, preferably 76 percent by weight or more, more preferably
80 percent by weight or more. In addition to the agglomerates composed of powdery
rubber particles and inorganic particles, the composite powder according to the present
invention may contain discrete inorganic particles. Especially when the content of
the inorganic particles is high inorganic particles are apt to occur outside the agglomerates.
[0022] The agglomerating state possessed by the composite powder according to the present
invention can be retained in the composition obtained by melt-blending the composite
powder with non-polar plastics(such as polypropylenes or polyethylenes). By subjecting
the composition to microtoming and then observing under a transmission electron microscope,
a photograph reflecting such an agglomerating state can be obtained (see Figure 1).
[0023] The composite powder according to the present invention can be prepared by intimately
mixing an irradiated or non-irradiated rubber latex with a slurry of inorganic particles
in a ratio corresponding to that of rubber particles to inorganic particles in the
composite powder according to the present invention, and then drying the resultant
mixture.
[0024] More particularly, the composite powder according to the present invention can be
prepared by:
a. intimately mixing a slurry of inorganic particles with a cross-linked synthetic
rubber latex to obtain a mixed latex and then drying the mixed latex; or
b. vulcanizing a rubber latex by high-energy irradiation in the absence or presence
of a cross-linking agent, intimately mixing a slurry of inorganic particles with the
irradiated rubber latex to obtain a mixed latex and then drying the mixed latex.
[0025] In the process for preparing the composite powder according to the present invention,
the slurry of inorganic particles is an aqueous suspension of inorganic particles
and can be commercially available slurries. However, prior to mixing with rubber latexes,
the commercially avaiable slurries are normally dispersed by means of a conventional
dispersing equipment(such as a high-shear dispersing and emulsifying machine, colloidal
mill and the like) so as to ensure that the solid particles in the slurries can be
homogeneously dispersed in water. If the slurry of inorganic particles are not commercially
available, they can be prepared by dispersing inorganic particles in a suitable amount
of water by means of conventional dispersing equipments to form a stable suspension,
which is then mixed with a rubber latex.
[0026] In the process for preparing the composite powder according to the present invention,
the inorganic particles are those commercially available in the art. There are no
restrictions on the type of the inorganic particles as long as the size thereof falls
within the scope of the present invention. However, the inorganic particles which
are unstable when encountering water are excluded. The inorganic particles can be
of any shape, such as spheres, ellipsoids, sheets, needles or irregular shapes. In
the view of three-dimensional point, the individual particles has an average size
of from 0.2 to 500nm, preferably from 0.5 to 100nm in at least one dimension.
[0027] The inorganic particles used in the process according to the present Invention can
be selected from elemental metals or alloys thereof, such as gold, silver, cupper,
iron or alloys thereof: metal oxides, such as aluminum oxide(Al
2O
3), magnesium oxide(MgO), titanium dioxide(TiO
2), iron sesquioxide(Fe
2O
3), ferroferric oxide(Fe
3O
4), silver oxide(Ag
2O), zinc oxide(ZnO) and the like; metal or non-metal nitrides, such as aluminum nitride(AIN),
silicon nitride(SiN
4) and the like; non-metal carbides, such as silicon carbide(SiC) and the like; non-metal
oxides, such as silicon dioxide(SiO
2) and the like; metal hydroxides, such as aluminum hydroxide(Al(OH)
3), magnesium hydroxide(Mg(OH)
2) and the like; metal salts, including metal carbonates, silicates, sulfates and the
like, such as calcium carbonate(CaCO
3), barium sulfate(BaSO
4), calcium sulfate(CaSO
4), silver chloride(AgCl) and the like; mineral earths, such as asbestos, talc, kaolin,
mica, feldspar, wollastonite, montmorillonite and the like; and the mixtures of two
or more of them.
[0028] In the process for preparing the composite powder according to the present invention,
the ratio of the weight of the rubber contained in the rubber latex(i.e., dry weight
or solid content of the rubber latex): to the weight of the inorganic particles contained
in the slurry of inorganic particles (i.e., dry weight of the slurry of inorganic
particles) is from 99.5 : 0.5 to 20 : 80, preferably from 99 : 1 to 50 : 50.
[0029] In the process variant a or b. for preparing the composite powder according to the
present invention, the mixed latex can be obtained by intimately mixing a slurry of
inorganic particles, an aqueous solution of water-soluble nucleating agent for plastics
and the irradiated rubber latex(in the process variant b.) or the cross-linked rubber
latex(in the process variant a.). The ratio of the dry weight of the irradiated rubber
latex or the cross-linked rubber latex to the weight of the nucleating agent contained
in the aqueous nucleating agent solution is from 99 : 1 to 50 : 50. preferably from
97 : 3 to 70 : 30. The composite powder thus obtained can improve the tougheness of
plastics and at the same time, promote the crystallization of crystalline plastics,
which results in further improvement in the rigidity of plastics. In the process according
to the present invention, there is no restriction on the water-soluble nucleating
agent for plastics as long as it is water-soluble and promotes the nucleation of plastics.
Sodium benzoate is preferably used.
[0030] In the process for preparing the composite powder according to the present invention,
it is possible to add the slurry of inorganic particles and optionally, an aqueous
solution of water-soluble nucleating agent for plastics to the irradiated rubber latex
or the cross-linked rubber latex while stirring so as to intimately mix them. There
are no particular restrictions on the concentrations of the rubber latex, the slurry
of inorganic particles and the aqueous nucleating agent solution. The drying can be
carried out by using the drying method for preparing the fully vulcanized powdery
rubber disclosed in the international Patent Publication WO 01/40356A1 and the International
Patent Publication WO 01/98395(filed on June 15, 2001, claiming the benefit of the
Chinese Patent Application No. 00109217.0 filed by the present applicants on June
15, 2000), that is to say, the drying can be carried out by means of a spray dryer,
with the inlet temperature and the outlet temperature being controlled to be 100 to
200°C and 20 to 80°C, respectively. The rubbers contained the composite powders obtained
by using the above process variants a, and b, has a gel content equal to that In the
cross-linked synthetic rubber latex in process variant a and that in the irradiated
rubber latex in process variant b., respectively.
[0031] After a series of experiments, the present inventors found that some rubber latexes
undergo a certain degree of cross-linking between the rubber molecules during their
synthesis, which results in rubber latexes having a certain degree of cross-linking.
Such rubber latexes are referred to as cross-linked rubber latexes. The Chinese Patent
Application No. 00130386.4(CN 1353131A) filed by the present applicants on November
3, 2000 mentioned such a cross-linked synthetic rubber latex, which has a gel content
of 80 percent by weight or more, preferably 85 percent by weight or more, Such a rubber
latex is per se cross-linked to a higher degree, and thus can be directly spray dried
to obtain powdery rubbers, without further irradiation cross-linwing. In the process
variant a. for preparing the composite powder according to the present invention,
such cross-linked synthetic rubber latexes are used as the starting materials. Cross-linked
synthetic rubber latexes can be selected from the group consisting of cross-linked
styrene-butadiene latex, cross-linked carboxylated styrene-butadiene latex, cross-linked
polybutadiene latex, cross-linked acrylonitrile-butadiene latex, cross-linked carboxylated
acrylonitrile-butadiene latex, cross-linked neoprene latex and cross-linked acrylic
latex.
[0032] In the process variant b, for preparing the composite powder according to the present
Invention, there are no restrictions on the rubber latexes as the starting materials.
For example, they can be rubber latexes, used for preparing the fully vulcanized powdery
rubbers In the International Patent Publications WO 01/40356A1 and WO 01/98395, such
as natural rubber latex, styrene-butadiene rubber latex, carboxylated styrene-butadiane
rubber latex, acrylonitrile-butadiene rubber latex, carboxylated acrylonitrile-butadiene
rubber latex, polybutadiene rubber latex, neoprene rubber latex, silicone rubber,
latex, acrylic rubber latex, butadiene-styrene-vinylpyridine rubber latex, isoprene
rubber latex, butyl rubber latex, ethylene-proptyene rubber latex, polysulfide rubber
latex, acrylate-butadiene rubber latex, urethane rubber latex, fluorlns rubber latex
and the like.
[0033] The rubber latexes used in the process variant b. for preparing the composite powder
according to the present invention can also include the cross-linked synthetic rubber
latexes used in the process variant a., that is to say, the cross-linked synthetic
rubber latexes can be used to prepare the composite powder according to the present
invention without irradiation(as in the process variant a.) or with irradiation(as
in the process variant b.), with the gel content of the rubber in the composite powder
obtained by the process variant b. being higher than that by the process variant a.
[0034] There are no particular restrictions on the solid content(i.e., dry weight) of the
rubber latexes used in the above two process variants, which Is normally from 20 to
70 percent by weight, preferably from 30 to 60 percent by weight, more preferably
from 40 to 50 percent by weight. The average particle size of the rubber particles
in these rubber latexes is from 20 to 2000 nm, preferably from 30 to 1500 nm, more
preferably from 50 to 500 nm. After irradiating the rubber latexes, the rubber particles
contained therein acquire a relatively high gel content(60 percent by weight or more),
or in the case of the cross-linked synthetic rubber latexes, the particle size of
the rubber particles is fixed due to the high gel content, thus after co-spraying
the rubber latex and the slurry of inorganic particles, the particle size of individual
rubber particles is consistent with that of the rubber particles contained in the
rubber latexes as the starting material, i.e., from 20 to 2000 nm, preferably from
30 to 1500 nm, more preferably from 50 to 500 nm, irrespective as of whether the rubber
particles are in the form of agglomerates or in free state.
[0035] In the process variant b. for preparing the composite powder according to the present
invention, the conditions for irradiating rubber latexes, including cross-linking
agents, irradiation doses, sources of high-energy irradiation and the like, are same
as those in the process for preparing fully vulcanized powdery rubbers disclosed in
the International Patent Publications WO 01/40358A1 and WO 01/98395. During the irradiation
of rubber latexes, a cross-linking agent is optionally used. The cross-linking agent
used can be selected from the group consisting of mono-, di-, tri-, tetra- or multi-functional
cross-linking agents, and any combination thereof. Examples of monofunctional cross-linking
agents include, but not limited to, octyl (meth)acrylate, Iso-octyl (meth)acrylate,
glycidyl (meth)acrylate; examples of difunctional cross-linking agents include, but
not limited to, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate,
diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, neopentyl
glycol di(meth)acrylate, divinylbenzene; examples of trifunctional cross-linking agents
include, but not limited to, trimethylolpropane tri(meth)acrylate, pentaerythritol
tri(meth)acrylate; examples of tetrafunctional cross-linking agents include, but not
limited to pentaerythritol tetra(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate;
examples of multi-functional cross-linking agents Include, but: not limited to dipentaerythritol
penta(meth)acrylate. In the context of the present application, the term "(meth)acrylate"
means acrylate or methacrylate. These cross-linking agents can be used alone or In
any combination, as long as they facilitate the vulcanization under irradiation.
[0036] The amount of the cross-linking agent added varies depending on the type and formulation
of the rubber latexes, arid is generally from 0.1 to 10 percent by weight, preferably
from 0.5 to 9 percent by weight, more preferably from 0.7 to 7 percent by weight,
based on the dry weight of the latexes.
[0037] In the process variant b. for preparing the composite powder according to the present
invention, the high-energy irradiation which can be used is selected from the group
consisting of cobalt sources(such as Co-50), UV ray sources and high-energy electron
accelerators, prefereby cobalt sources. The irradiation dose can be from 0.1 to 30
Mrad, preferably from 0.5 to 20 Mrad. The irradiation dose depends on the type and
formulation of the rubber latexes. Generally, the irradiation dose Is such that the
rubber latexes after vulcanization under irradiation have a gel content of 60 percent
by weight or more, preferably 75 percent by weight, more preferably 80 percent by
weight or more.
[0038] The composite powder according to the present invention, prepared by co-spraying
the rubber latexes, the slurry of inorganic particles and the like, comprises agglomerates
composed of powdery rubber particles and inorganic particles, with inorganic particles
being uniformly distributed either inside the agglomerats or both inside the agglomerates
and on the surfaces thereof, wherein the rubber particles themselves have a gel content
of 60 percent by weight or more, preferably 75 percent by weight or more, more preferably
80 percent by weight or more. In addition to the agglomerates composed of powdery
rubber particles and inorganic parties, the composite powder according to the present
invention may contain discrete inorganic particles. Especially when the content of
the inorganic particles is high, inorganic particles are apt to occur outside the
agglomerates.
[0039] The agglomerating state possessed by the composite powder according to the present
invention can be retained in the composition obtained by melt-blending the composite
powder with non-polar plastics (such as polypropylenes or polyethylenes). By subjecting
the composition to microtoming and then observing under a transmission electron microscope,
a photograph reflecting such an agglomerating state can be obtained (see Figure 1).
[0040] The composite powder according to the present invention can be dispersed in plastic
matrixes by conventional blending processes, wherein the rubber particles facilitate
the uniform dispersion of inorganic particles in the matrix and thus the agglomeration
of inorganic particles is substantial avoided. In non-polar rensin matrixes(such as
polypropylene or polyethylene), inorganic particles are uniformly distributed in the
agglomerates composed of inorganic particles and rubber particles, which results in
a good modification effect. In the case of resin matrixes which chemically react with
the rubber particles in the interface or have a large interaction with the rubber
particles in the interface, the rubber particles contained in the composite powder
according to the present invention can be dispersed in the resin matrixes in the form
of individual particles after melt-blending, and due to the fact that the inorganic
particles contained in the composite powder are uniformly dispersed between the rubber
particles, the ideal dispersion of the rubber particles in the resin facilitates the
dispersion of inorganic particles. For example, in the case of layered inorganic particles
like montmorillonite, by preparing a composite powder comprising montmorillonite particles
and rubber particles, montmorillonite can be dispersed in polar resin matrixes like
nylons in an exfoliated state by the action of rubber particles (as shown in Fig.
3), without the complicated organo-modification.
[0041] The process for preparing the composite powder according to the present Invention
is simple, convenient and easy to carry out, When the composite powder according to
the present invention Is used for toughening plastics, a better toughening effect
can be achieved, compared to using rubber elastic particles alone, and meanwhile,
the negative effects on rigidity and heat resistance of resins caused by the introduction
of elastic particles are reduced. Furthermore, the composite powder according to the
present invention can be advantageously used for the preparation of thermoplastic
elastomers,
[0042] The composite powder according to the present invention can be dispersed in plastics
very easily, thus can be mixed with various plastics to prepare a number of toughened
plastics and thermoplastic elastomers. The preparation of toughened plastics or thermoplastic
elastomers can be carried out by simply mixing the composite powder according to the
present invention and plastics in a certain proportion in conventional blending equipments
under conventional processing conditions, if necessary, in the presence of conventional
processing aids and compatilizers.
[0043] In the preparation of toughened plastics, the weight ratio of the composite powder
according to the present invention to plastics is from 0.5 : 99.5 to 50 : 50, preferably
from 1 : 99 to 30 : 70. The plastics to be toughened can be nylons, polypropylenes,
polyethylenes, polyvinyl chloride, polyurethanes, polyesters, polycarbonates, polyoxymethylene,
polystyrene, , polyphenylene oxide(PPO), polyphenylene sulfide(PPS), polyimides, polysulfones,
epoxy resins, unsaturated polyesters, phenolic resins, amino resins, alkyd resins,
diallyl phthalate resins, silicone resins or blends or mixtures thereof.
[0044] In the preparation of thermoplastic elastomers, the weight ratio of the composite
powder according to the present invention to plastics is from 30 : 70 to 75 : 25,
preferably from 50 : 50 to 70 : 30. The plastics which can be used are nylons, polypropylenes,
polyethylenes, polyvinyl chloride, polyurethanes, polyesters, polycarbonates, polyoxymethylene,
polystyrene, polyphenylene oxide(PPO), polyphenylene sulfide(PPS), polyimides, polysulfones,
epoxy resins, unsaturated polyesters, phenolic resins, amino resins, alkyd resins,
diallyl phthalate resins, silicone resins or blends or mixtures thereof.
Examples
[0045] The present invention is further described with reference to the following examples,
which shall not be construed as limiting the present Invention In any way. The scope
of the present invention will be defined in the appended claims.
Testing and characterizing method of the morphology of the composite powder:
[0046] The composite powder, propylene homopolymer powder or pellets(melt index: <5g/10min)
and an antioxidant(Irganox 1010, Ciba-Geigy) are compounded at a weight ratio of the
composite powder : polypropylene : 1010 of 100 : 10 : 0.5 in a high speed stirrer
for 1 minute. The blending and pelleting are carried out in a ZSK-25 twin-screw extruder(Wemer
& Pfleiderer Co., Germany), with the temperatures for each section of the extruder
being respectively 165°C, 180°C, 195°C, 195°C, 195°C and 195°C (die temperature).
The extruded strips are subjected to microtoming under -100°C, staining with O
5O
4 and then observing under a transmission electron microscope.
Example 1
[0047] 5kg of carboxylated butadiene-styrene rubber latex having a solid content of 50 percent
by weight(avallable from Beijing Yanshan Petrochemical Company, Brand: XSBRL-54B1,
average particle size of the rubber particles in latex: 150 nm) Is placed in a vessel,
75g of iso-octyl acrylate is added dropwise while stirring, and the stirring is continued
for 1 hour after the completion of addition. Thereafter, the rubber latex is Irradiated
with Co-60, with the irradiation dose being 2.5Mrad and the irradiation dose rate
being 50Gy/min. The rubber particles in the irradiated latex have a gel content of
92.6%. A slurry of calcium carbonate(Fine Chemical Factory of Beijing University of
Chemical Technology, solid content: 47.3%, average size in one dimension of the particles:
40 to 60nm) is compounded with the irradiated latex at a weight ratio of 50 : 50(on
dry basis) while stirring for 1 hour. The mixed latex is spray dried by means of a
spray dryer, with the inlet temperature and the outlet temperature being 140 to 160°C
and 40 to 60°C, respectively. A dried carboxylated butadiene-styrene rubber/calcium
carbonate composite powder 1 is then collected in a cyclone.
Example 2
[0048] 500kg of calcium carbonate powders(Fine Chemical Factory of Beijing University of
Chemical Technology, average size in one dimension of the particles: 40 to 60nm) are
mixed with 1 kg water in a vessel, the resultant mixture is then dispersed by means
of a high-shear dispersing and emulsifying machine to obtain a suspension, which is
then compounded with the irradiated carboxylated butadiene-styrene rubber latex(prepared
as in Example 1) at a weight ratio of 50 : 50(on dry basis) while stirring for 1 hour.
The mixed latex is spray dried by means of a spray dryer, with the inlet temperature
and, the outlet temperature being 140 to 160°C and 40 to 60°C, respectively. A dried
carboxylated butadiene-styrene rubber/calcium carbonate composite powder 2 is then
collected in a cyclone.
Example 3
[0049] 5kg of butadiene-styrene rubber latex having a solid content of 45 percent by weight(available
from Lanzhou Petrochemical Company, Brand: DINGBEN-50, gel content: 88.9% average
particle size of the rubber particles in latex: 100 nm) is placed in a vessel, 67.5g
of iso-octyl acrylate is added dropwise while stirring, and the stirring is continued
for 1 hour after the completion of addition. Thereafter, the rubber latex is irradiated
with Co-60, with the irradiation dose being 2.5Mrad and the irradiation dose rate
being 50Gy/min. The rubber particles in the irradiated latex have a gel content of
90.0%. A slurry of calcium carbonate(as in Example 1) is compounded with the irradiated
latex at a weight ratio of 90 : 10(on dry basis) while stirring for 1 hour. The mixed
latex Is spray dried by means of a spray dryer, with the inlet temperature and the
outlet temperature being 140 to 160°C and 40 to 60°C, respectively. A dried butadiene-styrene
rubber/calcium carbonate composite powder 1 is then collected in a cyclone.
Example 4
[0050] The procedure same as in Example 3 is followed, except that the butadiene-styrene
rubber latex, without irradiation, is directly compounded with the slurry of calcium
carbonate at a weight ratio of 80 : 20(on dry basis) while stirring for 1 hour. The
mixed latex is spray dried by means of a spray dryer, with the inlet temperature and
the outlet temperature being 140 to 160°C and 40 to 60°C, respectively. A dried butadiene-styrene
rubber/calcium carbonate composite powder 2 is then collected in a cyclone.
Example 5
[0051] The procedure same as in Example 3 is followed, except that the butadiene-styrene
rubber latex, without irradiation, is directly compounded with the slurry of calcium
carbonate and an aqueous solution of sodium benzoate(available from Wuhan Youjishiye
Corporation) at a weight ratio of 80 : 20: 10 (on dry basis) while stirring for 1
hour. The mixed latex is spray dried by means of a spray dryer, with the inlet temperature
and the outlet temperature being 140 to 160°C and 40 to 60°C, respectively. A dried
butadiene-styrene rubber/calcium carbonate composite powder containing the nucleating
agent is then collected in a cyclone.
Example 6
[0052] Sodium-based montmorillonite(available from Qinghe Factory, Zhangliakou, Hebel, the
particles can be dispersed as flakes of 1 to 20nm thick and 200 to 1000nm long) is
mixed with water In a concentration of 5 percent by weight, dispersed by means of
a high-shear disperser and then placed for more than one week. After that period,
the mixture is dispersed again by means of a high-shear disperser to obtain a stable
suspension, with the layers of sheet montmorillointe being sufficiently exfollated.
The irradiated butadiene-styrene rubber latex(prepared as in Example 3) is compounded
with the above slurry of montmorillonite at a weight ratio of 90 : 10(on dry basis)
while stirring for 1 hour. The mixed latex is spray dried by means of a spray dryer,
with the inlet temperature and the outlet temperature being 140 to 160°C and 40 to
60°C, respectively. A dried butadiene-etyrene rubber/montmorillonite composite powder
1 is then collected in a cyclone.
Example 7
[0053] The procedure same as in Example 6 is followed, except that the weight ratio of the
irradiated butadiene-styrene rubber latex to the sluny of sodium-based montmorillonite
is changed to 99 : 1 (on dry basia), with a dried butadiene-styrene rubber/ montmorillonite
composite powder 2 being obtained.
Example 8
[0054] Silicon dioxide powders(avarable from Shenyang Chemical Corporation, average size
in one dimension of its particles: 7 to 30 nm) are mixed with water In a concentration
of 5 percent by weight and then dispersed by means of a high-shear disperser to obtain
a stable suspension. 5kg of carboxylated acrylonitrile-butadiene rubber latex having
a solid content of 45 percent by welght(available from Lanzhou Petrochemical Company,
Brand: XNBRL, average particle size of the rubber particles in latex: 50 nm) is placed
in a vessel, 67.5g of iso-octyl acrylate is added dropwise while stirring, and the
stirring is continued for 1 hour after the completion of addition. Thereafter, the
rubber latex is irradiated with Co-60, with the irradiation dose being 2.5Mrad and
the irradiation dose rate being 50Gy/min. The rubber particles in the irradiated latex
have a gel content of 96.1 %. The irradiated acrylonitrile-butadiene rubber latex
is compounded with the above slurry of silicon dioxide at a weight ratio of 90 : 10(on
dry basis) while stirring for 1 hour. The mixed latex is spray dried by means of a
spray dryer, with the inlet temperature and the outlet temperature being 140 to 160°C
and 40 to 60°C, respectively. A dried carboxylated acrylonitrile-butadiene rubber/silicon
dioxide composite powder is then collected in a cyclone.
Example 9
[0055] The procedure same as in Example 8 is followed, except that the slurry of silicon
dioxide is replaced by the slurry of calcium carbonate(as in Example 1), with a dried
carboxylated acrylonitrile/calcium carbonate composite powder being obtained.
Example 10
[0056] Titanium dioxide powders(available from Beijing University of Chemical Technology,
average size in one dimension of its particles: 40 to 60 nm) are mixed with water
in a concentration of 20 percent by weight and then dispersed by means of a high-shear
disperser to obtain a stable suspension. The irradiated butadiene-styrene rubber latex(prepared
as in Example 3) is compounded with the above slurry of titanium dioxide at a weight
ratio of 95 : 5(on dry basis) while stirring for 1 hour. The mixed latex is spray
dried by means of a spray dryer, with the inlet temperature and the outlet temperature
being 140 to 160°C and 40 to 60°C, respectively. A dried butadiene-styrene rubber/titanium
dioxide composite powder is then collected in a cyclone.
Example 11
[0057] Magnesium hydroxide powders(avallable from Beijing University of Chemical Technology,
average size in one dimension of Its particles: 20 to 40 nm) is mixed with water in
a concentration of 20 percent by weight and then dispersed by means of a high-shear
disperser to obtain a stable suspension. 5kg of acrylonitrile-butadiene rubber latex
having a solid content of 45 percent by weight (available from the Latex Reseach Center,
Lanzhou Petrochemical Company, Brand: DINGJING-26, average particle size of the rubber
particles in latex: 100 nm) is placed in a vessel, 112.5g of trimethylolpropane triacrylate
is added dropwise while stirring, and the stirring is continued for 1 hour after the
completion of addition. Thereafter, the rubber.latex is irradiated with Co-60, with
the irradiation dose being 1.0Mrad and the Irradiation dose rate being 50Gy/min. The
rubber particles in the irradiated latex have a gel content of 90.0%. The irradiated
acrylonitrile-butadiene rubber latex is compounded with the above slurry of magnesium
hydroxide at a weight ratio of 40 : 60 (on dry basis) while stirring for 1 hour. The
mixed latex Is spray dried by means of a spray dryer, with the inlet temperature and
the outlet temperature being 140 to 160°C and 40 to 60°C, respectively. A dried acrylonitrile-butadiene
rubber/magnesium hydroxide composite powder is then collected in a cyclone.
Example 12
[0058] 5kg of butadiene-styrene-vinylpyridine rubber latex having a solid content of 40
percent by weight(available from Changzhihai Latex Company, Clxi, Zhejiang. Brand:
55555, average particle size of the rubber particles in latex: 100 nm) is placed in
a vessel, 100g of trimethylolpropane triacrylate is added dropwise while stirring,
and the stirring is continued for 1 hour after the completion of addition. Thereafter,
the rubber latex is irradiated with Co-60, with the irradiation dose being 2.5Mrad
and the irradiation dose rate being 50Gy/min. The rubber particles In the irradiated
latex have a gel content of 87.0%. The irradiated rubber latex Is compounded with
the slurry of montmorillonite(prepared as in Example 6) at a weight ratio of 95 :
5(on dry basis) while stirring for 1 hour. The mixed latex is spray dried by means
of a spray dryer, with the inlet temperature and the outlet temperature being 140
to 160°C and 40 to 60°C, respectively. A dried butadiene-styrene-vinylpyridine rubber/montmorillonite
composite powder is then collected in a cyclone.
Example 13
[0059] 50g of metallic silver powders (Zhengyuan Nanomaterial Engineering Company, Shangdong,
average size: 20 to 80nm) are mixed with 1kg water in a vessel and then dispersed
in a high-shear dispersing and emulsifying machine to obtain a suspension. The resultant
suspension is compounded with the irradiated carboxylated butadiene-styrene rubber
latex(prepared as In Example 1) at a weight ratio of 1 : 99(on dry basis) while stirring
for 1 hour. The mixed latex Is spray dried by means of a spray dryer, with the inlet
temperature and the outlet temperature being 140 to 160°C and 40 to 60°C, respectively.
A dried carboxylated butadiene-styrene rubber/metallic silver composite powder is
then collected in a cyclone.
Example 14
[0060] The butadiene-styrene-vinylpyridine rubber/montmorillointe composite powder prepared
as in Example 12 is compounded with Nylon 6(available from UBE, Japan, Brand: 1013B)
and antioxidant Irganox 1010(available, from Ciba-Geigy, Switzerland) at a weight
ratio of Nylon 6: the composite powder : 1010 of 100 : 15 : 0.3. The blending and
pelleting are carried out In a ZSK-25 twin-screw extruder(Werner & Pfleiderer:Co.,
Germany), with the temperatures for each section of the extruder being respectively
220°C, 235°C, 235°C, 235°C, 235°C and 235°C(die temperature). The extruded pellets
are injection-molded into standard test bars and then subjected to various tests of
mechanical properties. The results are listed in Table 1. Figure 3 is the micrograph
of the sample.
Comparative Example 1
[0061] The nylon pellets as in Example 14 are compounded with a powdery butadiene-styrene-vinylpyridine
rubber(obtained by directly spray drying the irradiated butadiene-styrene-vinylpyridine
rubber latex as in Example 12, without mixing the slurry of montmorillonite) and antioxidant
Irganox 1010 at a weight ratio of nylon : powdery butadiene-styrene-vinylpyridine
rubber : 1010 of 100 : 15 : 0.3. Standard test bars are obtained by extruding and
injection-molding as In Example 14 and then subjected to various tests of mechanical
properties. The results are listed in Table 1.
Comparative Example 2
[0062] The procedure as in Example 14 is followed, except that no composite powder is used.
Standard test bars are obtained by extruding and injection-molding as in Example 14
and then subjected to various tests of mechanical properties. The results are listed
in Table 1.
Example 15
[0063] The butadiene-styrene rubber/calcium carbonate composite powder containing a nucleating
agent prepared as in Example 5 is compounded with polypropylene pellets(available
from Luoyang Petrochemical Company, Brand: B-200, melt index: 0.35g/10min) and antioxidant
Irganox 1010(available from Ciba-Geigy, Switzerland) at a weight ratio of polypropylene
: the composite powder of 100 : 10, with the amount of the antioxidant being 0.25
part by weight per 100 parts by weight of the total weight of polypropylene and the
composite powder, the resultant mixture is mixed for 1 minute in a high speed stirrer.
The blending and pelleting are carried out in a ZSK-25 twin-screw extruder(Werner
& Pfleiderer Co., Germany), with the temperatures for each section of the extruder
being respectively 165°C, 190°C, 195°C, 195°C, 195°C and 195°C(die temperature). The
extruded pellets are injection-molded into standard test bars and then subjected to
various tests of mechanical properties. The results are listed in Table 1. Figure
1 is the micrograph of the sample.
Comparative Example 3
[0064] The procedure as in Example 15 is followed, except that no composite powder is used
and that polypropylene is compounded with the antioxidant at a weight ratio of 100
: 0.25. The extruded pellets are injection-molded into standard test bars and then
subjected to various tests of mechanical properties. The results are listed in Table
1.
Comparative Example 4
[0065] The procedure as In Example 15 Is followed, except that the butadiene-styrene rubber/calcium
carbonate composite powder containing a nucleating agent is replaced by a powdery
butadiene-styrene rubber containing sodium benzoate(prepared by adding 45g of sodium
benzoate to 1 kg of the butadiene-styrene rubber latex as in Example 3 while stirring,
continuing the stirring for 1 hour, spray drying the resultant mixed latex by means
of a spray dryer, with the inlet temperature and the outlet temperature being 125
to 145°C and 45 to 60°C, respectively, and then collecting the dried butadiene-styrene
rubber/sodium benzoate composite powder in a cyclone, the weight ratio of the butadiene-styrene
rubber to sodium benzoate in the powder: 100 : 10). The extruded pellets are injection-molded
into standard test bars and then subjected to various tests of mechanical properties,
The results are listed in Table 1.
Table 1
No. |
Tensile strength (MPa) |
Elongation at break (%) |
Izod notched impact strength (J/m)23°C |
Iod notched impact strength (J/m)-20°C |
Flexural strength (MPa) |
Flexural modulus (GPa) |
Heat distortion temperature (°C) 18MPa |
Ex. 14 |
60.8 |
25 |
118 |
90.1 |
85.7 |
2.01 |
69.2 |
Comp. Ex. 1 |
56.2 |
40 |
107 |
61.5 |
79.8 |
1.83 |
66.5 |
Comp. Ex. 2 |
82.4 |
16 |
34.4 |
29.8 |
111 |
2.41 |
67.4 |
Ex. 15 |
34.6 |
120 |
221 |
315 |
36.0 |
1.57 |
116.4 |
Comp. Ex 3 |
36.5 |
145 |
64.4 |
262 |
36.2 |
1.54 |
106.8 |
Comp. Ex.4 |
33.9 |
119 |
186 |
- |
35.9 |
1.53 |
116.0 |
Testing Standard |
GB 1040 |
GB 1040 |
GB 1843 |
GB 1843 |
GB 9341 |
GB 9341 |
GB 1634 |
Example 16
[0066] Polypropylene(Daging Huake Corporation, propylene homopolymer pellets melt index:
0.4g/10min) is intimately mixed with the butadiene-styrene rubber/calcium carbonate
composite powder 2 prepared as in Example 4 at a weight ratio of 50 : 50 in a high
speed mixer. The blending and pelleting are carried out in a ZSK-25 twin-screw extruder(Werner
& Pfleiderer Co., Germany), with the temperatures for each section of the extruder
being respectively 170°C, 190°C, 200°C, 210°C, 220°C and 210°C (die temperature).
The extruded pellets of the fully vulcanized thermoplastic elastomer are injection-molded
Into standard test bars and then subjected to various tests of mechanical properties.
The results are listed in Table 2.
Comparative Example 5
[0067] The procedure as in Example 16 is followed, except that the butadiene-styrene rubber/calcium
carbonate composite powder 2 is replaced by a powdery butadiene-styrene rubber(obtained
by directly spray drying the irradiated butadiene-styrene rubber latex as in Example
3, without mixing the slurry of calcium carbonate).The extruded pellets of the fully
vulcanized thermoplastic elastomer are injection-molded into standard test bars and
then subjected to various tests of mechanical properties. The results are listed In
Table 2.
Table 2
Sample |
Shore hardness(HD) |
Tensile strength at break(MPa) |
Permanent compression deformation(22hrs, 23°C), % |
Comp. Ex. 5 |
49 |
16.4 |
15.8 |
Ex.16 |
48 |
19.6 |
16.0 |
Example 17
[0068] 28.8g of epoxy resin prepolymer(Wuxi Resin Factory. Brand: E-44), 51.84g of Premix
1 (prepared as follows) and 54g of methyl-tetrahydrophthalic anhydride(Oriental Chemical
Factory, Jiaxing, Zhejlang) are weighted into a three-necked flask, heated by a thermostatic
water bath at 90°C and then mixed while stirring for 30 minutes. To the resultant
mixture is added 0.36g of triethanolamine(analytic pure, available from Beijing Yili
Fine Chemicals), and the mixture is evacuated while stirring for 5 minutes and then
is cast to a polytetrafluoroethylene mold preheated to 130°C. The mixture is precured
at 130°C for 1 hour, cooled for mold release and then is postcured at 110°C for 16
hours, thereby obtaining a cured product, which is then cut to pieces for determination
of various properties. The results are listed in table 3. Figure 2 Is the micrograph
of the sample.
Preparation of Premix 1:
[0069] 20 parts by weight of the carboxylated acrylonitrile-butadiene rubber/calcium carbonate
composite powder(prepared as follows) are mixed with 100 parts by weight of epoxy
resin prepolymer(same as above) and the resultant mixture is milled three times by
means of a three-roll mill, thereby obtaining Premix 1. Preparation of the carboxylated
acrylonitrile-butadiene rubber/calcium carbonate composite powder:
[0070] The irradiated carboxylated acrylonitrile-butadiene rubber latex(prepared by irradiating
the carboxylated acrylonitrile-butadiene rubber latex as in Example 8 in an irradiation
dose of 1Mrad in the presence of 5 percent by weight of trimethylolpropane triacrylate,
based on the dry weight of the carboxylated acrylonitrile-butadiene rubber latex,
with the gel content of rubber particles In the irradiated latex being 90.0%) is compounded
with a suspension of nano-calcium carbonate(prepared by dispersing 100 parts by weight
of nano-calcium carbonate cake(available from Beijing Nanuotaike Nanotech Company,
Brand: 113-SH, solid content: 50 percent by weight, average size in one dimension
of its particles: 40 to 60nm) in 400 parts by weight of water in a high-shear dispersing
and emulsifying machine) at a weight ratio of 80 : 20 (on dry weight), while stirring.
The mixed latex is then spray dried to obtain the carboxylated acrylonitrile-butadiene
rubber/calcium carbonate composite powder, with the inlet temperature and outlet temperature
being 140 to 160°C and 40 to 60°C, respectively.
Comparative Example 6
[0071] 72g of epoxy resin prepolymer (as in Example 17) and 54g of methyl-tetrahydrophthalic
anhydride(as in Example 17) are weighted into a three-necked flask, heated by a thermostatic
water bath at 90°C and then mixed while stirring for 30 minutes. To the resultant
mixture is added 0.36g of triethanolamine(as in Example 17), and the mixture is evacuated
while stirring for 5 minutes and then is cast to a polytetrafluoroethylene mold preheated
to 130°C, The mixture is precured at 130°C for 1 hour, cooled for mold release and
then is postcured at 110°C for 16 hours, thereby obtaining a cured product, which
is then cut to pieces for determination of various properties. The results are listed
in table 3.
Comparative Example 7
[0072] The procedure as in Example 17 is followed, except that Premix 1 Is replaced by Premix
2(prepared as follows). Various properties are determined and the results are listed
in table 3.
Preparation of Premix 2:
[0073] The irradiated carboxylated acrylonitrile-butadiene rubber latex(prepared by irradiating
the carboxylated acrylonitrile-butadiene rubber latex as in Example 8 in an Irradiation
dose of 1Mrad in the presence of 5 percent by weight of trimethylolpropane triacrylate,
based on the dry weight of the carboxylated acrylonitrile-butadiene rubber latex)
is spray dried to obtain the powdery carboxylated acrylonitrile-butadiene rubber having
a gel content of 90.0% and an average particle size of 90 nm, with the inlet temperature
and outlet temperature being 140 to 160°C and 40 to 60°C, respectively, 20 parts by
weight of the powdery carboxylated acrylonitrile-butadiene rubber are mixed with 100
parts by weight of epoxy resin prepolymer(as in Example 17) and the resultant mixture
is milled three times by means of a three-roll mill, thereby obtaining Premix 2.
Comparative Example 8
[0074] The procedure as in Example 17 is followed, except that the amount of the epoxy resin
prepolymer(as in Example 17) is changed into 50.4g, Premix 1 is replaced by 30.24g
of Premix 3(prepared as follows). Various properties are determined and the results
are listed In table 3.
Preparation of Premix 3:
[0075] 40 parts by weight of nano-calcium carbonate(Fine Chemical Factory of Beijing University
of Chemical Technology, average size in one dimension of its particles: 40 to 60 nm)
are mixed with 100 parts by weight of epoxy resin prepolymer(as in Example 17) and
the resultant mixture is milled three times by means of a three-roll mill, thereby
obtaining Premix 3.
Comparative Example 9
[0076] The procedure as in Example 17 is followed, except that 33.12g of the epoxy resin
prepolymer(as in Example 17), 41.5g of Premix 2(as in Comparative Example 7) and 6.02g
of Premix 3(as in Comparative Example 8) are mixed. Various properties are determined
and the results are listed in table 3.
Table 3
|
Weight ratio of toughener: resin |
Impact strength (kl/m2) |
Flexural strength (MPa) |
Flexural modulus (GPa) |
Heat distortion temerpature (°C) |
Tg(°C) |
Ex. 17 |
12:100 |
28.2 |
97.7 |
2.73 |
104.7 |
111.7 (DSC) |
Comp. |
0:100 |
11.8 |
104 |
3.13 |
101.3 |
105.8 (DSC) |
Ex. 7 |
12:100 |
21.4 |
94.5 |
2.56 |
104.9 |
113.1(DSC) |
Comp. EX.8 |
12:100 |
11.6 |
87.1 |
3.32 |
101.8 |
107.7 (DSC) |
Comp. Ex. 9 |
12:100 |
20.1 |
91.9 |
2.71 |
102.9 |
111.2 (DSC) |
1. A composite powder, comprising powdery rubber particles having a cross-linked structure
and inorganic partides distributed between said rubber particles.
2. The composite powder according to claim 1, wherein said inorganic : particles have
an average size of 0.2 to 500 nm in at least one dimension and are selected from elemental
metals or alloys thereof; metal oxides; metal or non-metal nitrides; non-metal carbides;
non-metal oxides; metal hydroxides; metal salts: mineral earths; and the mixtures
of two or more of them; and the weight ratio of the powdery rubber particles to the
inorganic particles is from 99.5 : 0.5 to 20 : 80.
3. The composite powder according to claim 2, wherein the weight ratio of the powdery
rubber particles to the inorganic particles is from 99 ; 1 to 50 : 50.
4. The composite powder according to claim 2, wherein said inorganic particles have an
average size of 0.5 to 100 nm in at least one dimension.
5. The composite powder according to claim 1, wherein said inorganic particles are selected
from gold, silver, cupper, iron, gold alloys, silver alloys, cupper alloys, iron alloys,
aluminum oxide, magnesium oxide, titanium dioxide, iron sesquioxide, ferroferric oxide,
silver oxide, zinc oxide, aluminum nitride, silicon nitride, silicon carbide, silicon
dioxide, aluminum hydroxide, magnesium hydroxide, calcium carbonate, barium sulfate,
calcium sulfate, silver chloride, asbestos, talc, kaolin, mica, feldspar, wollastonite,
montmorillonite, and the mixtures of two or more of them.
6. The composite powder according to claim 1, wherein said powdery rubber particles have
a gel content of 60 percent by weight or more.
7. The composite powder according to claim 1, comprising agglomerates composed of powdery
rubber particles and inorganic particles, with inorganic particles being uniformly
distributed elther inside the agglomerates or both inside the agglomerates and on
the surfaces thereof, wherein the rubber particles themselves have a gel content of
60 percent by weight or more.
8. The composite powder according to claim 1, wherein said rubber particles have a gel
content of 75 percent by weight or more.
9. A process for preparing the composite powder according to claim 1, comprising:
a. intimately mixing a slurry of inorganic particles with a cross-linked synthetic
rubber latex to obtain a mixed latex and then drying the mixed latex; or
b. vulcanizing a rubber latex by high-energy irradiation in the absence or presence
of a cross-linking agent, intimately mixing a slurry of inorganic particles with the
irradiated rubber latex to obtain a mixed latex and then drying the mixed latex.
10. The process according to claim 9, wherein the slurry of inorganic particles is an
aqueous suspension of inorganic particles.
11. The process according to claim 9, wherein said inorganic particles have an average
size of 0.2 to 500 nm in at least one dimension and are selected from elemental metals
or alloys thereof; metal oxides; metal or non-metal nitrides; non-metal carbides;
non-metal oxides; metal hydroxides; metal salts; mineral earths; and the mixtures
of two or more of them; and the weight ratio of the powdery rubber particles contained
in said rubber latex to the inorganic particles contained in said slurry is from 99.6
; 0.5 to 20 : 80.
12. The process according to claim 11, wherein the weight ratio of the powdery rubber
particles contained in said rubber latex to the inorganic particles contained in said
slurry is from 99 : 1 to 50 : 50.
13. The process according to claim 9, wherein during the preparation of said mixed latex,
an aqueous solution of water-soluble nucleating agents for plastics is added in a
weight ratio of the rubber particles contained In said latex to the nucleating agent
contained in said aqueous solution of 99 ; 1 to 50 : 50.
14. The process according to claim 13, wherein said nucleating agent is sodium benzoate.
15. The process according to claim 13, wherein the weight ratio of the rubber particles
contained in said latex to the nucleating agent contained in said aqueous solution
of 97 : 3 to 70: 30.
16. The process according to claim 11, wherein said inorganic particles have an average
size of 0.5 to 100 nm in at least one dimension.
17. The process according to claim 11, wherein said inorganic particles are selected from
gold, silver, cupper, iron, gold alloys, silver alloys, cupper alloys, iron alloys,
aluminum oxide, magnesium oxide, titanium dioxide, iron sesquioxide, ferroferric oxide,
silver oxide, zinc oxide, aluminum nitride, silicon nitride, silicon carbide, silicon
dioxide, aluminum hydroxide, magnesium hydroxide, calcium carbonate, barium sulfate,
calcium sulfate, silver chloride, asbestos, talc, kaolin, mica, feldspar, wollastonite,
montmorillonite, and the mixtures of two or more of them.
18. The process according to claim 9, wherein said cross-linked synthetic rubber latexes
used in a. have a gel content of 80 percent by weight or more.
19. The process according to claim 9, wherein said cross-linked synthetic rubber latexes
used in a, are selected from the group consisting of cross-linked styrene-butadiene
latex, cross-linked carboxylated styrene-butadiene latex, cross-linked polybutadiene
latex, cross-linked acrylonitrile-butadiene latex, cross-linked carboxylated acrylonitrile-butadiene
latex, cross-linked neoprene latex and cross-linked acrylic latex.
20. The process according to claim 9, wherein said rubber latexes used in b. are selected
from the group consisting of natural rubber latex, styrene-butadiene rubber latex,
carboxylated styrene-butediene rubber latex, acrylonitrile-butadiene rubber latex,
carboxylated acrylonitrile-butadiene rubber latex, polybutadiene rubber latex, neoprene
rubber latex, silicone rubber latex, acrylic rubber latex, butadiene-styrene-vinylpyridine
rubber latex, isoprene rubber latex, butyl rubber latex, ethylene-proplyene rubber
latex, polysulfide rubber latex, acrylate-butadiene rubber latex, urethane rubber
latex and fluorine rubber latex.
21. A composition useful for preparing toughened plastics or thermoplastic elastomers,
comprising plastics and the composite powder according to any of claims 1 to 8.
22. Use of the composite powder according to any of claims 1 to 8 in the preparation of
toughened plastics or thermoplastic elastomers.